One of the SHF models:

based on implicit solution of the constant pressure gradient equation:

where $//<![CDATA[ \begin{array}{l}\rho_o=\rho_o(T_i, \, p_i)\end{array} //]]>$ и  $//<![CDATA[ \begin{array}{l}\rho_w=\rho_w(T_i, \, p_i)\end{array} //]]>$ – oil and water densities at initial formation temperature $//<![CDATA[ \begin{array}{l}T_i\end{array} //]]>$ and pressure $//<![CDATA[ \begin{array}{l}p_i\end{array} //]]>$.

This model requires reliable and representative data bank on capillary pressure at sandface conditions.

See also

Petroleum Industry / Upstream / Subsurface E&P Disciplines / Petrophysics / Capillary pressure @model 

References

SPE 71326, B. Harrison (Enterprise Oil), X.D. Jing (Imperial College, London), Saturation Height Methods and Their Impact on Volumetric Hydrocarbon in Place

Estimates, 2001